U.S. patent application number 13/126897 was filed with the patent office on 2011-09-08 for multi-carriers managing device and method and sleep mode operating method of terminal.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Eunkyung Kim, Hyun-Jae Kim, Juhee Kim, Kyung Soo Kim.
Application Number | 20110216684 13/126897 |
Document ID | / |
Family ID | 42275579 |
Filed Date | 2011-09-08 |
United States Patent
Application |
20110216684 |
Kind Code |
A1 |
Kim; Eunkyung ; et
al. |
September 8, 2011 |
MULTI-CARRIERS MANAGING DEVICE AND METHOD AND SLEEP MODE OPERATING
METHOD OF TERMINAL
Abstract
A multi-carriers management device of a communication system
supporting multi-carriers requests a terminal attempting to enter a
sleep window to change a primary carrier, and transmits a control
message to the terminal through the changed primary carrier during
the sleep window.
Inventors: |
Kim; Eunkyung; (Seoul,
KR) ; Kim; Juhee; (Daejeon, KR) ; Kim;
Hyun-Jae; (Incheon, KR) ; Kim; Kyung Soo;
(Daejeon, KR) |
Assignee: |
SAMSUNG ELECTRONICS CO.,
LTD.
Suwon-city, Gyeonggi-do
KR
|
Family ID: |
42275579 |
Appl. No.: |
13/126897 |
Filed: |
October 30, 2009 |
PCT Filed: |
October 30, 2009 |
PCT NO: |
PCT/KR09/06317 |
371 Date: |
April 29, 2011 |
Current U.S.
Class: |
370/311 |
Current CPC
Class: |
H04W 52/0229 20130101;
H04W 52/0216 20130101; H04L 27/2601 20130101; H04L 5/02 20130101;
H04W 36/24 20130101; Y02D 30/70 20200801; H04L 5/001 20130101; H04W
72/042 20130101; H04L 5/008 20130101; H04W 72/0453 20130101; H04W
52/0206 20130101; Y02D 70/20 20180101; H04L 5/0098 20130101 |
Class at
Publication: |
370/311 |
International
Class: |
H04W 52/02 20090101
H04W052/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 30, 2008 |
KR |
10-2008-0107177 |
Oct 27, 2009 |
KR |
10-2009-0102497 |
Claims
1. A method for a base station of a communication system for
supporting multi-carriers to manage the multi-carriers, comprising:
requesting a first terminal attempting to enter a sleep window to
change a primary carrier; and transmitting a control message to the
first terminal through the primary carrier that is changed for the
sleep window.
2. The method of claim 1, wherein the control message includes a
traffic indication message.
3. The method of claim 1, wherein the requesting includes:
selecting a carrier that is usable in common by the greatest number
of terminals from among a first terminal and a plurality of second
terminals from among carriers that are usable by the first terminal
and carriers that are usable by the plurality of second terminals
having entered the sleep window; and requesting the first terminal
to change the selected carrier as the primary carrier when the
first terminal can use the selected carrier.
4. The method of claim 3, wherein requesting of the first terminal
includes: transmitting a sleep mode response message including
information on the selected carrier to the first terminal.
5. The method of claim 1, further including requesting at least one
of a plurality of second terminals having entered the sleep window
during a listening window to change the primary carrier.
6. The method of claim 5, further comprising selecting a carrier
that is usable in common by the greatest number of terminals from
among the first terminal and the plurality of the second terminals
from among carriers that are usable by the first terminal and
carriers that are usable by the plurality of second terminals; and
requesting the at least one second terminal to change the selected
carrier as a primary carrier when the at least one second terminal
can use the selected carrier.
7. The method of claim 6, wherein requesting of the at least one
second terminal includes transmitting a media access control (MAC)
management message including information on the selected carrier to
the at least one second terminal.
8. A sleep mode operation method of a terminal in a communication
system supporting multi-carriers, comprising: receiving a request
to change a primary carrier from a base station when entering a
sleep window; changing the primary carrier and entering a sleep
mode; and receiving a control message from the base station through
the changed primary carrier.
9. The sleep mode operation method of claim 8, wherein the control
message includes a traffic indication message.
10. The sleep mode operation method of claim 8, wherein the
receiving of a request includes receiving a sleep mode response
message including information on a primary carrier to be changed
from the base station.
11. The sleep mode operation method of claim 8, further including
receiving a request to change the primary carrier from the base
station during a listening window after the sleep window.
12. The sleep mode operation method of claim 11, wherein receiving
of a request to change the primary carrier from the base station
during a listening window includes receiving a media access control
(MAC) management message including information on the primary
carrier to be changed from the base station.
13. The sleep mode operation method of claim 8, wherein the control
message is received during the listening window after the sleep
window.
14. A device for managing multi-carriers by a base station of a
communication system supporting the multi-carriers, comprising: a
communicator for requesting a first terminal attempting to enter a
sleep window to change a primary carrier, wherein a control message
is transmitted through the changed primary carrier during the sleep
window.
15. The device of claim 14, wherein the control message includes a
traffic indication message.
16. The device of claim 14, wherein the device further includes a
carrier selector for selecting a carrier that is usable in common
by the greatest number of terminals from among the first terminal
and a plurality of second terminals from among carriers that are
usable by the first terminal and carriers that are usable by the
plurality of second terminals having entered the sleep window, and
when the selected carrier is available for the first terminal, the
communicator requests the first terminal to change the primary
carrier with the selected carrier.
17. The device of claim 16, wherein the communicator includes
information on the selected carrier in the sleep mode response
message and transmits the same to the first terminal.
18. The device of claim 14, wherein the communicator requests at
least one of a plurality of second terminals having entered the
sleep window to change the primary carrier during a listening
window.
19. The device of claim 18, wherein the device further includes a
carrier selector for selecting a carrier that is usable in common
by the greatest number of terminals from among the first terminal
and the plurality of second terminals from among carriers that are
usable by the first terminal and carriers that are usable by the
plurality of second terminals, and the communicator requests the at
least one second terminal to change the primary carrier with the
selected carrier when the at least one second terminal can use the
selected carrier.
20. The device of claim 19, wherein the communicator includes
information on the selected carrier in the media access control
(MAC) management message and transmits the same to the at least one
second terminal.
Description
TECHNICAL FIELD
[0001] The present invention relates to a multi-carriers management
method and device, and a sleep mode operation method for a
terminal.
BACKGROUND ART
[0002] In general, one of multi-carriers is used as a primary
carrier and the other is used as a subcarrier.
[0003] In a wireless communication system supporting
multi-carriers, a base station transmits a control message to a
terminal through primary carriers. That is, a traffic indication
message for notifying a terminal that has entered a sleep window of
whether there are data that will be transmitted by a base station
is transmitted to the terminal from the base station through the
primary carrier.
[0004] However, when primary carriers used by a plurality of
terminals that have entered the sleep window are different, the
base station has to transmit the traffic indication message by
using the primary carriers used by the respective terminals, and
hence the radio resource is inefficiently used. Also, the base
station increases a load according to transmission of the traffic
indication message.
[0005] The above information disclosed in this Background section
is only for enhancement of understanding of the background of the
invention and therefore it may contain information that does not
form the prior art that is already known in this country to a
person of ordinary skill in the art.
DISCLOSURE OF INVENTION
Technical Problem
[0006] The present invention has been made in an effort to provide
a multi-carriers management method and device for reducing a load
caused by message transmission by a base station and efficiently
managing multi-carriers, and a sleep mode operation method for a
terminal.
Solution to Problem
[0007] An exemplary embodiment of the present invention provides a
method for a base station of a communication system for supporting
multi-carriers to manage multi-carriers, including requesting a
first terminal attempting to enter a sleep window to change a
primary carrier, and transmitting a control message to the first
terminal through the primary carrier that is changed for the sleep
window.
[0008] Yet another embodiment of the present invention provides a
sleep mode operation method of a terminal in a communication system
supporting multi-carriers, including receiving a request to change
a primary carrier from a base station when entering a sleep window,
changing the primary carrier and entering the sleep mode, and
receiving a control message from the base station through the
changed primary carrier.
[0009] Yet another embodiment of the present invention provides a
device for managing multi-carriers by a base station of a
communication system supporting the multi-carriers, including a
communicator for requesting a first terminal attempting to enter a
sleep window to change a primary carrier, wherein a control message
is transmitted through the changed primary carrier during the sleep
window.
Advantageous Effects of Invention
[0010] According to an embodiment of the present invention, the
multi-carriers are efficiently managed in the wireless
communication system for supporting the multi-carriers.
[0011] Also, the radio resource is efficiently used by efficiently
managing the multi-carriers for the terminal in a power save
mode.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 shows a multi-carriers wireless communication system
according to an exemplary embodiment of the present invention.
[0013] FIG. 2 shows multi-carriers.
[0014] FIG. 3 shows a flowchart of a sleep mode operation for a
terminal according to an exemplary embodiment of the present
invention.
[0015] FIG. 4 shows an operation by a carrier management device
according to an exemplary embodiment of the present invention.
[0016] FIG. 5 shows a method for forming a terminal group according
to an exemplary embodiment of the present invention.
[0017] FIG. 6 shows a flowchart of a method for a terminal
according to an exemplary embodiment of the present invention to
change a primary carrier.
[0018] FIG. 7 shows a schematic diagram of a carrier management
device according to an exemplary embodiment of the present
invention.
MODE FOR THE INVENTION
[0019] In the following detailed description, only certain
exemplary embodiments of the present invention have been shown and
described, simply by way of illustration. As those skilled in the
art would realize, the described embodiments may be modified in
various different ways, all without departing from the spirit or
scope of the present invention. Accordingly, the drawings and
description are to be regarded as illustrative in nature and not
restrictive. Like reference numerals designate like elements
throughout the specification.
[0020] Throughout the specification and claims, unless explicitly
described to the contrary, the word "comprise" and variations such
as "comprises" or "comprising" will be understood to imply the
inclusion of stated elements but not the exclusion of any other
elements.
[0021] In the specification, a terminal may indicate a mobile
station (MS), a mobile terminal (MT), a subscriber station (SS), a
portable subscriber station (PSS), user equipment (UE), and an
access terminal (AT), and it may include entire or partial
functions of the mobile station (MS), the mobile terminal, the
subscriber station, the portable subscriber station, the user
equipment, and the access terminal.
[0022] In the specification, a base station (BS) may indicate an
access point (AP), a radio access station (RAS), a nodeB (Node-B),
an evolved Node-B (eNB), a base transceiver station (BTS), and a
mobile multihop relay (MMR)-BS, and it may include entire or
partial functions of the access point, the radio access station,
the nodeB, the evolved Node-B, the base transceiver station, and
the mobile multihop relay-BS.
[0023] A multi-carriers management method and device in a
multi-carriers wireless communication system according to an
exemplary embodiment of the present invention will now be described
with reference to accompanying drawings.
[0024] FIG. 1 shows a multi-carriers wireless communication system
according to an exemplary embodiment of the present invention, and
FIG. 2 shows multi-carriers.
[0025] Referring to FIG. 1, the multi-carriers wireless
communication system includes a terminal 100 and a base station
200.
[0026] The terminal 100 is an endpoint of a radio channel, and
supports multi-carriers having the frequency bandwidths FA1 to FAn
shown in FIG. 2. Therefore, the terminal 100 communicates with the
base station 200 by using the multi-carriers with the frequency
bandwidths FA1 to FAn.
[0027] The base station 200 communicates with the terminal 100 that
is provided in a cell area, and includes a multi-carriers
management device (not shown) for managing the multi-carriers that
are allocated to the terminal 100.
[0028] The multi-carriers management device sets one of the
multi-carriers to be a primary carrier and the other to be a
secondary carrier. The primary carrier represents a carrier that is
used to transmit/receive various types of control information and
data between the terminal 100 and the base station 200, and the
secondary carrier indicates an additional carrier that is used to
transmit/receive data while the terminal is transmitting/receiving
control information through the primary carrier.
[0029] FIG. 3 shows a flowchart of a sleep mode operation of a
terminal according to an exemplary embodiment of the present
invention.
[0030] Referring to FIG. 3, the terminal 100 attempting to enter
the sleep mode sets a sleep period to transmit a sleep mode request
message SLP-REQ to the base station 200 (S300). In this instance,
the sleep mode request message SLP-REQ may include a minimum sleep
window parameter, a maximum sleep window parameter, and a listening
window parameter.
[0031] Upon receiving the sleep mode request message SLP-REQ, the
base station 200 allocates a sleep identifier of the terminal 100,
determines the sleep period based on contents that are included in
the sleep mode request message SLP-REQ, and transmits a sleep mode
response message SLP-RSP to the terminal 100 (S310). In this
instance, the sleep mode response message SLP-RSP includes sleep
identifier information, sleep start time M, minimum sleep window,
and maximum sleep window of the terminal 100.
[0032] The terminal 100 having received the sleep mode response
message SLP_ RSP enters the sleep window during which the terminal
100 receives no data for the sleep window starting from the sleep
start time M (S320).
[0033] When the sleep window has expired, the terminal 100 enters a
listening window (S330). The terminal 100 having entered the
listening window receives a traffic indication message for
notifying whether there are data that are standing by for
transmission during the sleep window from the base station 200
(S340). The terminal 100 checks whether there are data that are
standing by for transmission during the sleep period from the base
station 200 through the traffic indication message. The traffic
indication message is transmitted through the primary carrier that
is allocated to the terminal 100.
[0034] That is, when there are no data that are standing by for
transmission during the sleep window, the base station 200 sets a
corresponding field D of the traffic indication message to be 0 and
transmits 0 to the terminal 100 (S340), and the terminal 100 enters
the sleep window again (S350) when there are no data standing by
for transmission during the sleep window according to the result of
checking the traffic indication message. In this instance, the
sleep window entered by the terminal 100 is set to be equal to or
greater than a previous sleep window within the limit of the
maximum sleep windows depending on the setting method.
[0035] When the sleep window has expired, the terminal 100 enters a
listening window (S380).
[0036] Meanwhile, there are data that are to be transmitted to the
terminal 100 that has entered during the sleep window, the base
station 200 buffers the data (S360), and sets the corresponding
field D of the traffic indication message to be 1 and transmits the
traffic indication message to the terminal 100 and the terminal 100
that has entered in the listening window receives the traffic
indication message (S370).
[0037] When there are data that are standing by for transmission
during the sleep window, the base station 200 transmits data to the
terminal 100 in the listening window and the terminal 100 receives
the data from the base station 200 in the listening window
(S390).
[0038] Then, when the listening window has expired, the terminal
100 enters a sleep window (S400).
[0039] In addition, when the terminal 100 is managed as a terminal
group, the base station 200 sets a group bitmap (not shown) for
indicating whether there are data to be transmitted to at least one
terminal belonging to the terminal group to the corresponding
field, and sets a traffic bitmap (not shown) for indicating whether
there are data to be transmitted to each terminal belonging to each
terminal group. The base station 200 can display the existence
state of the data to be transmitted to the terminal belonging to
the terminal group to the group bitmap and the traffic bitmap with
bits. For example, when the base station 200 manages 32 terminal
groups, each terminal group has 32 terminals, a sleep identifier of
the terminal 100 belongs to the first terminal group, and there are
data that are to be transmitted to the terminal 100, the base
station 200 sets a group bitmap (not shown) to be 32 which
corresponds to the number of terminal groups and sets the most
significant bit (MSB) for indicating the first terminal group from
among 32 bits to be "1" to thereby notify that there are data that
will be transmitted to at least one terminal from among the
terminals that belong to the first terminal group. The base station
200 sets the traffic bitmap (not shown) to be the 32 bits that
correspond to the number of terminals belonging to the first
terminal group, and sets the bit for indicating the terminal 100 to
be "1" from among the 32 bits to notify that there are data that
are to be transmitted to the terminal 100.
[0040] FIG. 4 shows an operation by a carrier management device
according to an exemplary embodiment of the present invention, and
FIG. 5 shows a method for forming a terminal group according to an
exemplary embodiment of the present invention.
[0041] Referring to FIG. 4, when the terminal 100 supporting the
multi-carriers attempts to enter the sleep mode, the multi-carriers
management device selects the carriers that can be used in common
by the greatest number of terminals from among candidate carriers
usable by the terminal 100 attempting to enter the sleep mode and
candidate carriers usable by the terminal having entered the sleep
mode (S410).
[0042] The multi-carriers management device groups the terminal 100
attempting to enter the sleep mode for each selected carrier and
the terminals having entered the sleep mode to form a terminal
group (S420), and sets the selected carrier to be the primary
carrier of the terminals belonging to each terminal group
(S430).
[0043] The multi-carriers management device transmits information
on the selected carrier to request the terminal belonging to each
terminal group to change the current primary carrier (S440).
[0044] The multi-carriers management device may not transmit the
information on the selected carrier to the corresponding terminal
when the carrier selected from among the terminal belonging to the
terminal group is set to be the primary carrier.
[0045] For example, it is assumed that the cell area managed by the
base station 200 has 6 terminals a, b, c, d, e, and f, carriers and
primary carriers available by the terminals a, b, c, d, e, and f
are set as shown in FIG. 5, the terminals b, c, d, e, and f have
entered the sleep window, and the terminal a attempts to enter the
sleep window.
[0046] The multi-carriers management device selects the carriers
that are usable in common by the greatest number of terminals from
among the multi-carriers FA1 to FA5 based on the candidate carriers
FA1, FA2, and FA3 that are usable as primary carriers by the
terminal a attempting to enter the sleep window and the candidate
carriers FA1, FA3, FA4/FA2, FA3, FA4/FA1, FA3, FA5/FA3, FA4,
FA5/FA2, FA4 that are usable as primary carriers by the terminals
b/c/d/e/f having entered the sleep window. In this instance, since
the carrier FA3 is used in common by the greatest number of
terminals a, b, c, d, and e, the terminals a, b, c, d, and e that
can use the carrier FA3 are formed to be a single terminal group
G1, and the other terminal f is formed to be another terminal group
G2.
[0047] The multi-carriers management device sets the carrier FA3 to
be the primary carrier of the terminals a, b, c, d, and e belonging
to the terminal group G1 in the case of the terminal group G1, and
maintains the primary carrier FA2 that is set for the terminal f in
the case of the terminal group G2. The multi-carriers management
device transmits information on the carrier FA3 that is selected
through the sleep mode response message SLP-RSP to the terminal a
attempting to enter the sleep window to request to change the
primary carrier, and it transmits information on the carrier FA3
that is selected through a media access control (MAC) management
message during the listening window to the terminals b, c, d, and e
having entered the sleep window to request to change the primary
carrier. In this instance, it is possible to add a field to the
sleep mode response message SLP-RSP and the MAC management message,
and include the information on the selected carrier FA3 in the
added field.
[0048] The terminal a attempting to enter the sleep window from
among the terminals a, b, c, d, and e belonging to the terminal
group G1 changes the primary carrier with the carrier FA3 and
enters the sleep window, and the terminals b, c, d, and e having
entered the sleep window from among the terminals a, b, c, d, and e
belonging to the terminal group G1 changes the primary carrier with
the carrier FA3 during the listening window. In this instance, in
the case of the terminals b and d, the multi-carriers management
device can request the terminals a, c, and e to change the primary
carrier since the carrier FA3 is set to be the primary carrier.
[0049] Accordingly, the base station 200 can transmit the traffic
indication message by using a single carrier FA3 to the respective
terminals a, b, c, d, and e belonging to the terminal group G1, and
so the other carrier can be used for another purpose, thereby
enabling efficient management of the multi-carriers.
[0050] Further, when the base station 200 transmits the traffic
indication message once by using a single carrier FA3, the
respective terminals a, b, c, d, and e belonging to the terminal
group G1 can check the traffic indication message, and the load
caused by transmission of the traffic indication message by the
base station 200 is reduced.
[0051] FIG. 6 shows a flowchart of a method for a terminal
according to an exemplary embodiment of the present invention to
change a primary carrier.
[0052] Referring to FIG. 6, the terminal 100 attempting to enter
the sleep mode receives the primary carrier change request by
receiving information on the selected carrier from the base station
200 (S610). For example, in the case of the terminal a attempting
to enter the sleep window, information on the selected carrier can
be included in the sleep mode response message SLP-RSP, and the
terminal a can receive a primary carrier change request by
receiving a sleep mode response message from the base station. In
the case of the terminals b, c, d, and e having entered the sleep
window, information on the selected carrier may be included in the
MAC management message during the listening window, and the
terminals b, c, d, and e can receive a primary carrier change
request through receipt of the MAC management message.
[0053] The terminal 100 determines whether the current primary
carrier information established to the terminal 100 corresponds to
information on the carrier that is transmitted by the base station
200 (S620).
[0054] When the current primary carrier information does not
correspond to the carrier information provided by the base station
200, the terminal 100 changes the primary carrier with the carrier
that corresponds to the information on the carrier provided by the
base station 200 (S630), and enters the sleep mode (S650). When the
current primary carrier information corresponds to the carrier
information provided by the base station 200, the terminal 100
maintains the established primary carrier (S640) and enters the
sleep mode (S650).
[0055] The terminal having entered the sleep mode performs the same
operation as the terminal 100 attempting to enter the sleep mode,
thereby changing the primary carrier and maintaining the current
primary carrier.
[0056] FIG. 7 shows a schematic diagram of a carrier management
device according to an exemplary embodiment of the present
invention.
[0057] Referring to FIG. 7, a multi-carriers management device 210
includes a carrier selector 212 and a communicator 214.
[0058] The carrier selector 212 selects carriers that are usable in
common by the greatest number of terminals from among the terminals
attempting to enter the sleep window and the terminals having
entered the sleep window from among the candidate sub-carriers that
are usable by the terminal attempting to enter the sleep window and
the subcarriers that are usable by the terminals having entered the
sleep window among the terminals belonging to the cell area covered
by the base station 200.
[0059] The carrier selector 212 groups the terminals attempting to
enter the sleep window and the terminals having entered the sleep
window for respective selected carriers as a terminal group, and
sets the selected carrier to be the primary carrier to be used by
the terminal of each terminal group.
[0060] The communicator 214 transmits carrier information selected
by the terminal group to the terminal to request to change the
primary carrier. In this instance, the communicator 214 can include
information on the selected carrier in the sleep mode response
message SLP-RSP to request the terminal attempting to enter the
sleep window to change the primary carrier, and can include
information on the selected carrier in the MAC management message
to request the terminal having entered the sleep window to change
the primary carrier.
[0061] The base station 200 transmits the traffic indication
message to the terminal 100 by using the primary carrier.
[0062] The above-described embodiments can be realized through a
program for realizing functions corresponding to the configuration
of the embodiments or a recording medium for recording the program
in addition to through the above-described device and/or method,
which is easily realized by a person skilled in the art.
[0063] While this invention has been described in connection with
what is presently considered to be practical exemplary embodiments,
it is to be understood that the invention is not limited to the
disclosed embodiments, but, on the contrary, is intended to cover
various modifications and equivalent arrangements included within
the spirit and scope of the appended claims.
* * * * *